The invention pertains to a cyclone separator with a housing essentially rotation-symmetrical about a longitudinal axis, an inlet located in the vicinity of a front surface of the housing for an essentially tangential inlet of a fluid containing disperse substances and at least one outlet for the dispersed substances and at least one outlet for the cleaned fluid.
In the known cyclone separators of the kind described above, due to the design the degree of separation of the smallest solid particles (dispersed substances) whose density differs very little from the density of the fluid, is in general quite small, so that the fluid is improperly cleaned from these dispersed substances.
Therefore, it is the problem of the present invention to create a cyclone separator with an improved degree of separation.
Due to the invented cyclone separator, the degree of separation will be improved significantly, so that even dispersed substances which have a minor density difference in comparison to the fluid can be dependably separated. Thus the cleaned fluid can be sent, e.g., directly to control and regulation equipment or to high pressure pumps without any additional filtering steps, and can be used, for example, in sludge suction carts for cleaning of effluent channels to generate liquid streams at high pressure.
The cyclone separator according to this invention features a considerably improved efficiency (degree of separation).
For example, according to the first design solution, at a specified inlet speed of the fluid to be cleaned (fluid with dispersed substances), the rotary pulse of the fluid to be cleaned is increased by the placement of the inlet at a ring channel surrounding the housing, due to the greater distance to the longitudinal axis of the housing, and according to the second design, by the rotation of the rotor turning in the cyclone separator. Thus, the inertial forces (e.g., centrifugal forces) occurring in the cyclone separator can be increased, so that the separation effect for substances of different density will be improved.
Due to the formation of at least a portion of the housing wall at the level of the ring channel in the form of a flow rectifier connecting the ring channel to the interior of the housing, according to the first design, the fluid to be cleaned will be guided with much less turbulence into the interior of the cyclone housing, so that a steady wall flow without interfering secondary flow and with greatly reduced turbulence will form right in the inlet region. Due to this nearly complete rectification of the flow, the fluid to be cleaned will perform a well-defined rotational motion about the longitudinal axis of the housing, starting at the inlet region, so that right in this region the centrifugal forces will effectively contribute toward separation of the dispersed substances.
Due to the dish shaped bottom wall inclined toward the longitudinal axis of the housing, the fluid to be filtered will be guided continuously in the direction of the longitudinal axis of the housing. Thus, as the radius decreases, the rotational velocity of the rotating fluid to be cleaned will increase, so that the separating effect for substances with different density will increase.
Due to the tube extending concentric to the longitudinal axis, the primary rotation flow about the longitudinal axis of the invented cyclone separator will move concentric to the housing. This likewise improves the separating effect, since the flow is of very defined formation, especially in regions with very high flow velocities, like that occurring in the vicinity of the bottom wall.
Since the tube is also serving as outlet for the cleaned fluid and protrudes past the bottom wall in the direction of the inlet, it is necessary that the fluid flow coming from the inlet and rotating about the longitudinal axis be reversed at the bottom wall in the direction of the inlet, so that at least a portion of the fluid to be cleaned will be guided along the tube in the direction of the inlet. In order that the fluid to be cleaned can flow off through the tube, it must additionally be diverted by about 180 degrees. Thus, with each change of direction of the fluid to be cleaned, inertial forces will occur which additionally promote the separating effect of substances of different density. These forces are all the greater, the larger the flow velocities and the smaller the radii for the change of direction of the fluid flow. Due to the centrifugal effects described above, and in particular also due to the two changes in direction of the fluid to be cleaned, at the tube positioned concentric to the longitudinal axis, we obtain a clean fluid which is essentially cleaned free of dispersed substances, which is why this tube serves as outlet for it.
The dispersed substances are carried off through the outlet openings in the bottom wall, and due to the fluid flow, preferably a coagulation of the dispersed substances is prevented and they can thus be fully eliminated.
In one expedient embodiment of the first design solution, the flow rectifier extends along the perimeter of the housing wall. Thus, in a favorable manner, the flow is directed essentially rotation-symmetrical into the housing, so that a well-defined, nearly turbulence-free, rotation-like primary flow will form in the rotation-symmetrical housing. The flow rectifier can thus have a meshed-grid-like (screen-like) or honeycomb-like structure, depending on the fluid to be cleaned, the speed of the incoming fluid and the amount of turbulence of the inlet fluid. The flow rectifier can also be composed of rods positioned parallel to the longitudinal axis, e.g., along the perimeter of the housing, to form a lattice structure, or it can be formed by gaps in the housing wall running parallel to the longitudinal axis. In this case, the individual channels of the flow rectifier can be linear or curved toward the interior of the housing, in order to control the fluid flowing through the flow rectifier accordingly. The inlet of the flow into the interior of the housing can be affected also by the angle of the channels of the flow rectifier relative to the direction of the inlet fluid. For example, the gaps in the housing wall forming a flow rectifier can be formed at an angle to the particular radial plane, instead of being in a radial direction, for example, so that the fluid flowing into the interior of the housing will have preferably a tangential speed component, so that in the interior of the housing an enhanced rotational flow will form around this longitudinal axis.
Furthermore, several flow rectifiers can also be set up along the perimeter of the housing wall, and each flow rectifier will extend over a portion of the housing wall at the level of the ring channel. Thus the flow rectifiers positioned in this configuration can be similar to or also different from each other.
Preferably the housing wall will be of cylindrical shape at the level of the inlet region, so that preferably the formation of a defined rotational primary flow will take place right in the inlet region.
In an additional, preferred design format, the housing wall is cylindrical-shaped along the longitudinal axis between the inlet region and the dish-like bottom surface. But it can also have a conical shape running in the direction of the bottom surface, or the dish shape of the bottom wall can continue up to the level of the inlet region.
In an additional, expedient embodiment, the bottom wall is connected concave to the outlet for the cleaned fluid, so that preferably a well-defined flow deflection of the fluid to be cleaned will occur toward the inlet. This will likewise promote the amount of separation between fluid and the dispersed substances.
In an additional, preferred design embodiment of the cyclone separator according to this invention, a ventilation valve is provided on the housing in the vicinity of the inlet. Thus it is possible in a favorable manner, to send the cleaned fluid to high pressure pumps or control devices where an inlet of air is to be prevented.
The cyclone separator according to this invention can have preferably an additional outlet tube which runs concentric to the longitudinal axis and in sections within the tube for the outlet of the cleaned fluid, such that an annulus for the outlet of the cleaned fluid is formed between the two tubes, and such that the second tube protrudes in the direction of the inlet past the tube serving as outlet for the cleaned fluid and forms an additional outlet. Thus, depending on the volume of the flow through the two tubes, which can be controlled, for example, by suitable values (such as magnetic valves), a fractional separation of the cleaned fluid or of the dispersed substances is possible. For example, floating substances can be eliminated through the second tube.
The invented cyclone separator in yet another favorable design format can have a filter device operating according to the retention principle located in front of the outlet for the cleaned fluid. Thus, in a favorable manner, the filter effect for the cleaned fluid will be increased, so that the cleaned fluid can also be sent even to sensitive control devices or high-pressure pumps, for example. In this manner, the filter device can be composed of a hollow cylindrical filter placed concentrically along the longitudinal axis, and the one end of the filter will be connected to the outlet for the cleaned fluid.
Preferably, in conjunction with the filter device, there will be in the flowing fluid, at a short distance from one surface region of the filter, at least one flow control surface, such that a nozzle effect increasing the rate of flow is exerted onto the portion of the fluid passing through between flow control surface and the surface region of the filter. Based on the nozzle effect increasing the rate of flow, preferably the static pressure on the filter surface will decrease at the surface region of the filter located roughly opposite the flow control surface, so that the filter cake will be detached in the filter. In addition, with an appropriate shape and positioning of the flow control surface, with a suitable gradient between filter outer and filter inner surface, there will be a reversal of the direction of flow through the filter due to the reduced static pressure, that is, a portion of the filtrate will flow back into the fluid to be cleaned, so that the filter residue will be additionally detached from the surface of the filter facing the fluid to be cleaned. This filter residue can then again be exposed to the inertial forces described above, and will then be separated through the outlet for the dispersed substances. Due to this self-cleaning process of the regions of the filter surface in the vicinity of the nozzle effect, filters with considerably smaller filter openings can be used and thus a much improved degree of separation of the cyclone separator can be achieved. Furthermore, the filter can be operated much longer.